This invention relates to apparatus for packaging a wide variety of fiber optic circuit components upon a common support in association with electrical circuit components.
It is conventional to independently package the passive components of a fiber optic circuit on a passive platform. The platform is typically constructed from a single piece of metal. The fiber runs are machined in the platform along with seats for the passive components. In addition, the components on the passive platform are sensitive to damp heat and as a result, the entire unit must be hermetically sealed within a housing or the like. The bottom surface of the housing is equipped with a thermal patch which carries away excessive heat. Passive components housed in the passive platform unit may include, but are not limited to fiber coils, couplers, isolators, filters and fiber coils. The platform is expansion matched to the optical fiber of which these components are assembled.
The passive platform packaging technique, as evidenced by its widespread acceptance, works well in practice, however, it has certain disadvantages which the present invention overcomes. Separating the passive components of the fiber optic circuit from the active components and the electrical circuitry which supports the active components results in an inefficient utilization of space. Also, bringing light carrying fibers in and out of the hermetically sealed platform housing is difficult to achieve and is also expensive. Additional components are also mounted in the housing to monitor environmental conditions to insure that they are within acceptable limits.
Some electrical circuitry used in association with active fiber optic components should be ideally positioned as near as possible to the active component it services. For example, it is well known that a photodetecting monitor used in a fiber optic circuit will exhibit more effective and reliable operational results when mounted in close proximity with supporting circuitry. This type of close compatible mounting cannot be accomplished using a conventional passive platform arrangement.
A fixed passive platform mounted inside a hermetically sealed enclosure furthermore does not afford the flexibility needed to accommodate newly evolving and more innovative opto-electrical architecture. For example, the architecture of some optical devices require that a laser pump be mounted together with passive optical components which, in turn, calls for special considerations for handling waste heat.
Although some devices have been proposed in the literature for integrating optical circuitry and electrical circuitry, none of these devices provide a universal solution to the many problems related to integrating these two types of circuits.